1. Field of the Invention
The present invention relates to motorcycles.
2. Description of the Related Art
In a motorcycle, front and rear suspensions are conventionally provided in front and rear portions of a vehicle body, respectively, in order to absorb an impact from the ground and stabilize the vehicle body. The rear suspension is located below a seat of the motorcycle, and is often disposed substantially perpendicularly with respect to the ground. Therefore, a position of the seat is unfortunately raised by a height of the rear suspension. Since a space located below the rear suspension cannot be utilized efficiently, an exhaust system component such as a silencer is disposed laterally of the motorcycle, which disadvantageously degrades an agile appearance of the vehicle body.
In a motorcycle it is desired that from the viewpoint of providing favorable contact between a rider's foot and the ground and enhancing vehicle operability, a seat position should be lowered and a seat width in a vehicle width direction (hereinafter referred to as a “seat lateral width”) should be reduced. To achieve this result, a method for lowering a seat position is disclosed in JP-A-2000-85670, JP-A-2003-127965, and JP-A-2011-79343, for example. In the disclosed method, a rear suspension through which a cross member extending between a pair of right and left main frames and rear arms are connected to each other is disposed substantially horizontally with respect to the ground. When a rear suspension located below a seat is disposed substantially horizontally with respect to the ground, a height of the rear suspension can be lowered and thus a seat position can be lowered as compared with a case where a rear suspension is disposed substantially perpendicularly. Besides, when a rear suspension is disposed substantially horizontally, a space located below the rear suspension can be utilized efficiently.
A seat lateral width is decided depending on a shape of each main frame disposed below the seat. Hence, in order to reduce a seat lateral width, a distance between portions of a pair of right and left main frames located below the seat has to be reduced in a vehicle width direction. However, in the technique disclosed in JP-A-2000-85670, the pair of right and left main frames are connected to each other at positions located outward of the rear arms, and therefore, a distance between the main frames in a vehicle width direction cannot be smaller than a distance between the rear arms in the vehicle width direction. In the technique disclosed in JP-A-2003-127965, the rear suspension is offset toward the right one of the pair of main frames, and not only the rear suspension but also an exhaust pipe is arranged in the vehicle width direction. Therefore, the distance between the main frames in the vehicle width direction cannot be reduced, and in addition, a torsional load is unfortunately applied to the cross member. In the technique disclosed in JP-A-2011-79343, the rear suspension is offset toward the right one of the pair of main frames, and not only the rear suspension but also a component such as a battery is arranged in the vehicle width direction. Therefore, the distance between the main frames in the vehicle width direction cannot be reduced, and in addition, a torsional load is unfortunately applied to the cross member.